There is a large number of patents directed to the detection of a predetermined chemical or biomolecule in a solution by use of a piezoelectric crystal microbalance, for example, U.S. Pat. Nos. 4,735,906, 4,789,804, and 5,705,399. However, when the presence of several individual chemicals or biomolecules (analytes) are to be determined in the same solution aliquot, then it would be advantageous to have a system, device and method that can simultaneously handle a plurality of microbalances with flow cells which are individually specific for one of the analytes to be detected. Such a system, device and method would be particularly useful for screening of a large number of samples in a short time period, and in cases where the solution aliquot to be tested is small and a number of analytes are to be detected in the same solution aliquot. To avoid time-consuming and less practical regeneration of the cells for multiple use, especially for screening purposes, it would be advantageous to have a disposable pre-coated piezoelectric crystal mounted in a flow cell for screening of a large number of samples. When the sensor surface is inactive after use, the whole flow cell can be replaced.